Metrics of memory

Think of all the people you once knew, but no longer see. Regardless of how much time has passed. The 80/20 rule describes lots of phenomena. 20% of words account for 80% of word usage, 20% of music gets 80% of the plays. Pareto's Law, Zipfian distribution, however you learned it in school. The less frequent 80% is the long tail. Applied to memory, we'd have something like: 80%: Yup, this person existed, e.g. Facebook friends. 16%: People associated with stronger memories, good or bad, e.g. shared adventures, or what the hell was I thinking? 3.2%: I'll never forget this person, but I don't necessarily think about them every day. Deceased/estranged family and friends, long-term exes, people who shared singular moments. 0.8%: This person is a core memory in my life. I think about them every day. Only you know what people you'd categorize here. I suspect most social media grew from our hopes that we'd re-engage with people in the latter groups, when statistics and reality deliver us much…